Seizure Propagation Maps in Patients with Refractory Epilepsy

Epilepsy impacts approximately 50 million people worldwide, yet pharmacological treatment fails to achieve seizure freedom in one-third of patients, resulting in drug-resistant epilepsy. The most effective treatment to render refractory epilepsy patients seizure-free is surgical resection of the seizure onset zone. Nevertheless, only around 55% of patients become seizure-free after epilepsy surgery. Eligibility for surgery is assessed through various tests, including long-term electroencephalography (EEG), to localize the seizure onset zone and track the spread of seizure activity. Using Dynamical Imaging of Coherent Sources (DICS), a technique that traces the origin of oscillatory brain activity based on the seizure EEG data, the seizure propagation over time can be mapped in the brain. These propagation maps provide insights into patient-specific seizure dynamics, highlighting how seizure spread may vary across subjects, seizures, and frequency bands. In this study, we developed the pipeline to map the seizure propagation and tested it using multiple seizures. In the future, we want to validate these propagation maps based on intracranial records and seizure semiology. Furthermore, we want to identify biomarkers for predicting post-surgical seizure freedom based on these propagation patterns.